Commit ea45b600 authored by Lv Yunlong's avatar Lv Yunlong Committed by Vinod Koul

dmaengine: Fix a double free in dma_async_device_register

In the first list_for_each_entry() macro of dma_async_device_register,
it gets the chan from list and calls __dma_async_device_channel_register
(..,chan). We can see that chan->local is allocated by alloc_percpu() and
it is freed chan->local by free_percpu(chan->local) when
__dma_async_device_channel_register() failed.

But after __dma_async_device_channel_register() failed, the caller will
goto err_out and freed the chan->local in the second time by free_percpu().

The cause of this problem is forget to set chan->local to NULL when
chan->local was freed in __dma_async_device_channel_register(). My
patch sets chan->local to NULL when the callee failed to avoid double free.

Fixes: d2fb0a04 ("dmaengine: break out channel registration")
Signed-off-by: default avatarLv Yunlong <lyl2019@mail.ustc.edu.cn>
Reviewed-by: default avatarDave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20210331014458.3944-1-lyl2019@mail.ustc.edu.cnSigned-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 88cd1d61
......@@ -1086,6 +1086,7 @@ static int __dma_async_device_channel_register(struct dma_device *device,
kfree(chan->dev);
err_free_local:
free_percpu(chan->local);
chan->local = NULL;
return rc;
}
......
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